Abstract: A biaxially oriented laminated polyester film which has excellent dimensional stability to environmental changes such as temperature and humidity variations and excellent flatness and windability. A biaxially oriented laminated polyester film comprising a film layer B on one side of a film layer A and having a surface roughness (RaB) on the film layer B side which is 1.0 nm or more larger than the surface roughness (RaA) on the film layer A side, wherein at least one of the film layers comprises an aromatic polyester (I) composed of a glycol component and a dicarboxylic acid component containing 5 mol % or more and less than 80 mol % of a recurring unit represented by the following formula (A): wherein RA is an alkylene group having 1 to 10 carbon atoms.

Abstract: A biaxially oriented polyester film which has a Young's modulus (YMD) in the film machine direction (YMD) of 6.5 GPa or more and a Young's modulus in the width direction (YTD) of 8.2 to 9.8 GPa and is used as a base film for magnetic recording tapes of linear recording system, and a magnetic recording tape of linear recording system comprising the same as a base film. There are provided a biaxially oriented polyester film which has excellent dimensional stability, especially dimensional stability in the width direction and is suitable for use as a base film for magnetic recording tapes of linear recording system and a magnetic recording tape comprising the same.

Abstract: An object of the invention is to provide such an oriented polyester film that has a constant thickness, and is excellent in dimensional stability at a high temperature and dimensional stability to temperature change in a working temperature range. The invention relates to an oriented polyester film containing as a major component of a substrate layer polyethylene -2,6-naphthalene dicarboxylate, being stretched at least in one direction, and having a film thickness of from 12 to 250 ?m, wherein (1) a coefficient of linear thermal expansion ?t at a temperature of from 30 to 100° C. is from 0 to 15 ppm/° C. in both longitudinal and width directions of the film, and (2) a thermal shrinkage rate at 100° C. for 10 minutes is 0.5% or less in both longitudinal and width directions of the film.

Abstract: The invention provides a magnetic recording medium substrate product which enables enhancement of contact strength between a substrate end surface and a soft magnetic layer, as well as suppression of occurrence of corrosion, a magnetic recording medium including the substrate product, which exhibits no deterioration of electromagnetic conversion characteristics and has excellent durability and a magnetic recording and reproducing apparatus including the magnetic recording medium. The magnetic recording medium substrate product includes a disk-shaped non-magnetic substrate having a circular hole in a center portion thereof, and having a chamfer formed at least one of a portion between a main surface on which a magnetic layer is to be formed and an outer end surface and a portion between the main surface and an inner end surface defining the circular hole, wherein the chamfer has a surface roughness (Ra) falling within a range of 4.0 ??Ra?100 ?, preferably 4.0 ??Ra?50 ?, as measured by means of an AFM.

Abstract: Disclosed herein is an optical article having a top layer with a structured surface that collimates light, a core layer secured to the top layer opposite the structured surface, and a bottom layer secured to the core layer opposite the top layer. Either the top layer or the core layer includes a first extrudable polymer having a flexural modulus of greater than 2.5 GPa, and the other layer includes a second extrudable polymer having a flexural modulus of 2.5 GPa or less, an impact strength of greater than about 40 J/m, and tensile elongation at break of greater than about 5%. The bottom layer includes a third extrudable polymer. The bottom layer of the optical article may be structured to diffuse light. One or two optical articles may be secured to an optical film such as a polarizer film. Methods and display devices are also disclosed herein.

Abstract: A leader tape has, on at least one face of a support, a coating layer that contains a powder and a binder, which is characterized in that the center line average roughness (Ra) of at least one face of the leader tape is from 10 to 60 nm, the leader tape is used in a magnetic recording and reproduction device where the line recording density is at least 100 kfci, and the difference between the recording track width and the reproduction track width is from 0 to 16 ?m.

Abstract: A leader tape in which an non-magnetic under layer that contains a powder and a binder and a magnetic upper layer are sequentially laminated on at least one side of a support, a center line average roughness (Ra) of a surface of the support is from 30 to 50 nm, and a center line average roughness (Ra) of the multi layer coated surface is larger than that (Ra) of an opposite surface of the support, and the difference is at most 4 nm.

Abstract: A magnetic recording medium comprising a support having provided thereon a magnetic layer, wherein a smooth coating layer having a thickness of from 0.10 to 1 ?m, surface roughness of 5 nm or less, and 20 or less per 900 ?m2 of the protrusions having a height of 20 nm or more measured by an interatomic force microscope (AFM) is provided on the surface of at least one side of the support. And a method for producing a magnetic recording medium comprising a support having provided thereon a magnetic layer, which comprises providing a smooth coating layer having a thickness of from 0.10 to 1 ?m, surface roughness of 5 nm or less, and 20 or less per 900 ?m2 of the protrusions having a height of 20 nm or more measured by an interatomic force microscope (AFM) on the surface of at least one side of the support, and forming at least the magnetic layer on the smooth coating layer without performing rolling-up operation.

Abstract: It is a magnetic recording medium for which favorable values for all of reproduced output, noise level and error rate can be obtained, and which is also superior in terms of storage stability. A magnetic recording medium (10), which has a configuration in which a magnetic layer (3) comprised of a maghemite thin film containing cobalt is formed on a tape-shaped substrate (1) comprised of aromatic polyimide, and in which the substrate (1) is 3 to 10 ?m in thickness, and 5 to 30 nm in its ten-point average roughness (SRz) of the surface on which the magnetic layer (3) is formed, and the magnetic layer (3) is 10 to 50 nm in thickness, 0.1 to 3.0 nm in center plane average thickness (SRa), and 2,000 to 4,000 Oe (158,000 to 316,000 A/m) in in-plane coercivity, is made.

Abstract: A polyester film for magnetic recording media includes a coating layer containing fine particles and organic compounds formed on surface A at one side of the polyester film, and fine surface protrusions formed at a density of 3×106 to 1×108 protrusions/mm2 on surface A. The polyester film satisfies at least one of the following conditions: (a) the mean diameter of the fine surface protrusions is in the range of 5 to 60 nm, and, among the fine surface protrusions, the density of fine surface protrusions with a height of 20 nm or more is 3,000 protrusions/mm2, and (b) the mean diameter of the fine surface protrusions is in the range of 5 to 100 nm, the mean height of the fine surface protrusions is in the range of 5 to 30 nm, and the degree of cohesion of the fine surface protrusion is less than 15%.

Abstract: The present invention provides a polyester film particularly useful as a base film for a magnetic recording medium such as cassette-type magnetic tape of a digital recording mode and a production process thereof. The polyester film is produced by irradiating UV light onto a surface of a film in a non-stretched stage or a stage prior to the completion of stretching to form fine protrusions on the surface. The fine protrusions on the film surface are specified by the ratio of 10-point average roughness Rz to center line average roughness Ra (Rz/Ra) on the surface (less than 20), the difference in concentration of carboxyl groups between the surface layer part and the inside of the film, and the number of fine protrusions.

Abstract: A magnetic recording medium comprising a backcoating layer, a support, and a magnetic layer containing ferromagnetic powder, the backcoating layer having 800 to 1500 projections of 50 nm or more and less than 75 nm in height per 6400 ?m2 and 600 or less projections of 75 nm or more in height per 6400 ?m2.